This is just plain madness. A nuclear bunker buster? Do they seriously contend that a depth of 50 feet, the most a bunker buster could penetrate, would contain the blast and subsequent FALLOUT from a nuclear bomb?

Are they insane?

here we have the Pentagon trying to convince congress that... well... see for yourself.

WASHINGTON - The Pentagon wants the U.S. Congress to restore funding for research into a "bunker buster" nuclear bomb, which lawmakers dropped from the budget last year, officials said on Tuesday.

Defense Secretary Donald Rumsfeld wrote a memo last month to his counterpart at the Energy Department suggesting the administration ask for funds over the next two years to finish a study into the possible development of the Robust Nuclear Earth Penetrator.

The weapon under study would burrow into the earth to demolish hardened and deeply buried targets.

In November, Congress omitted about $27 million for the research sought by the Bush administration for the current fiscal year. Congressional opponents of the research argued that even studying the possibility of making such a weapon takes nuclear warfare out of the realm of the unthinkable and encourages adversaries of America to develop nuclear weapons.

...snip

I know this article doesn't mention it, and there's probably a reason for that. But do any of you have any idea, any idea at all how deep a nuclear device has to be in order to contain the radioactive fallout generated by the blast?

That's the question for this thread. How deep does the Robust Nuclear Earth Penetrator have to penetrate in order to ensure that noradioactive fallout escapes.